Air filters for heavy-duty transportation applications and also various internal combustion engines are designed to protect engines by forcing intake air to pass though a filtration process prior to entering the engine chamber. This is accomplished by forcing or sucking air through a pleated media air filter with a specific pass through efficiency prior to entering the engine chamber. This process allows for air intake into the engine chamber while preventing particulates from entering the engine. Air filtration efficiency is measured in terms of air flow, dust holding capacity, restriction, and final efficiency which is typically measured by amount of duct fed verses amount of duct blocked by the filter.
Existing air filtration products for transportation applications come in various shapes, sizes, number of pleats and specific efficiencies. The most prevalent air filter shapes for transportation applications are frustoconical and cylindrical. Cylindrical and frustoconical filters consist of pleated layers of filter media (usually cotton), wire mesh, and an inner support layer made up expanded metal bound together in polymer composite on either ends or with metal end caps. The inner support layer is required to prevent inward collapse of the filter unit during both storage and use. Currently in the vast majority of cylindrical and frustoconical air filters the inner support layer is made up of expanded metal, which greatly increases air resistance. The existing expanded metal inner support solution presents greater surface area for air to have to pass though. This prevents maximum air intake, which is a factor in greater engine performance, while proving no considerable advantage for filter efficiency.